The present invention generally relates to pin inserting guides, and more particularly, to guides for inserting thin, flexible, elongated pins.
Orthopaedic surgeons frequently find it necessary to insert elongated, thin cathode pins. These pins are introduced percutaneously and through a portion of bone, such that the exposed tip of the pin comes to rest directly in the non-union site of a fracture. The introduction of such cathode pins is known in the art. These cathode pins are typically utilized in conjunction with a particular method of electrical bone growth stimulation. This method is more particularly described in a Zimmer, Inc. brochure entitled, "The Alternate Treatment of Fracture Nonunion, Electrical Stimulation to Induce Osteogenesis." This brochure is identified as Zimmer Literature No. B-2360-1 .COPYRGT. 1979.
The cathode pins which are utilized are very thin, elongated stainless steel pins. The pins are insulated with a thin Teflon.RTM. coating of approximately 0.001 inch, which covers the entire length of the pin except for both the extreme distal tip portion and the extreme proximal end portion. The distal tip portion includes a sharp end point for penetration into the bone.
The thin, elongated cathode pins are flexible and easily bendable, and consequently, when they are attached to a drilling device, and drilled into the body, they are subject to various inflections, bending, etc. A prior art Cathode Pin Inserter has been used in conjunction with a hand-operated drill to facilitate the percutaneous insertion of these cathode pins. This prior art device is illustrated end described on pages 8 through 11 of the above-referenced literature No. B-2360-1 and is identified as Product No. 5012-04.
This inserter consists of a stabilizer metal bar mechanism which holds a thin plastic tube in place. The stabilizing mechanism is attached to a suitable drilling device. The pin is positioned in and extends from the chuck of the drilling device. The stabilizing mechanism supports the elongated plastic tube which is positioned in alignment with the pin, such that the mid-portion of the pin can be inserted through a small channel in the plastic tube, hence partially stabilizing the pin. Approximately 1 to 11/2 inches of the cathode pin projects from the end of the plastic tube support. If additional pin length is required, the stabilizing bar can be retracted toward the chuck and drill by loosening a bolt, sliding a moveable bar portion and retightening the bolt. If still more pin length is required for insertion, the plastic guide tube can be unscrewed and repositioned and potentially removed. This inserter involves time-consuming positioning of parts, and readjustment of parts in order to insert additional length of pin.
While the prior art inserter device described above is currently used with a hand-operated drill, this type of inserter could be adapted for use with a power instrument.